1. Field of the Invention
The present invention relays to an electro-magnetic relay structured to simultaneously open/close two circuits with uniform contact contact force.
2. Description of the Related Art
Traditionally, a small electro-magnetic relay capable of controlling two circuits, with large electricity capacity, high cut-off performance and superior anti-shock/vibration characteristic is known.
For example, an electro-magnetic relay in which an armature tip presses the center of a card block being a member bridging these circuits and the driving force of the armature is conveyed to movable contacts via the card block when driving the contacts of two parallel circuits is proposed.
Specifically, in this electro-magnetic relay, it is designed in such a way that force concentrated to one point of the armature tip or a narrow area close to one point can be distributed in two directions via the card block to drive two circuits (see, for example, the abstract and FIG. 2 of Patent Document 1: Japanese Patent Application No. 2005-340062).
When the force concentrated to one point is uniformly distributed in two directions as described above, the contact contact force (so called “contact pressure”) of the two circuits becomes uniform and its contact resistance also becomes the same as a rule. Therefore, there is no problem.
However, when the above is experimented using the structure of the electro-magnetic relay of Patent Document 1, it is found that the uniformity of the contact pressure is broken due to positional deviation and the like and the contact resistance is easy to become uneven, since the point pressed by an armature (power point) is above a contact contact part (action point).